To be honest, lots of people have told me that that bit is problematic, and relying on it just causes trouble. I don’t want to maintain two versions of Everson Mono. It might be better to talk to the people responsible for cygwin and Mintty. I’m willing to discuss it further, but at this stage, if that’s the cause that it will only use monospaced fonts, why not ask them about Everson Mono?
Michael